* gdb.base/callfuncs.exp: Remove the compiler info file prior to
attempting to regenerate it. Eliminate use of a temporary file
and just generate the info file directly. Source it immediately,
for consistency of use.
* gdb.base/corefile.exp: Ditto
* gdb.base/exprs.exp: Ditto.
* gdb.base/funcargs.exp: Ditto.
* gdb.base/langs.exp: Ditto.
* gdb.base/list.exp: Ditto.
* gdb.base/mips_pro.exp: Ditto.
* gdb.base/nodebug.exp: Ditto.
* gdb.base/opaque.exp: Ditto.
* gdb.base/ptype.exp: Ditto.
* gdb.base/scope.exp: Ditto.
* gdb.base/setvar.exp: Ditto.
* gdb.base/signals.exp: Ditto.
* gdb.base/whatis.exp: Ditto.
* gdb.c++/templates.exp: Ditto.
* gdb.c++/virtfunc.exp: Ditto.
* gdb.c++/virtfunc.exp: Use contents of gcc_compiled to decide
whether or not to add -lstdc++ to the compile command line args.